Gyoja or Anja has the following meanings.
Gyoja means a person who follows ascetic practices
Originally its use was not limited to Buddhism only, but was used in all the Indian ancient religions; gyoja's penance such as fasting or sitting on a batch of needles are especially famous. It is also known that Shaka had been doing penance before he attained enlightenment. In China and Japan, "gyoja" came to mean a person who is in charge of Shugendo (ascetic and shamanistic practice in mountainous sites). EN no Ozunu (A semi-legendary holy man noted for his practice of mountain asceticism during the second half of the 7th century), the originator of Shugendo, is also called En no Gyoja.
Anja is a worker in the Buddhist temple, who does chores such as rice milling or gathering firewood, does not become a priest, and remains as secular. Especially many anja are in Chinese Zen sect temples. It is famous that Rokuso Eno (the sixth leader Eno) had been in charge of rice milling as Ro-anja at the temple of Goso Konin (the fifth leader Konin) on Mt. Obai when Eno was acknowledged as the sixth leader by Konin. Following this, in present days of Japanese Zen sect temples, a priest who takes care of higher rank priests or works as a secretary may be called anja.
Gyoja means Goku SON of the "Saiyuki" (journey to the west).
As a custom of hiki (taboo against using one's personal name), to avoid using the imina (personal name) 'Goku,' it is expressed as 'SON gyoja' or 'gyoja.'
This expression derived from the name "Saru no gyoja" (pilgrim of monkey) who guarded Sanzo Hoshi (Genjosanzo) in an anecdote '大唐三蔵取經詩話' in the So period of China.